Blohm
The Blohm & Voss BV 141 was a World War II German tactical reconnaissance aircraft. It is notable for its uncommon structural asymmetry. Although the Blohm & Voss BV 141 performed well, it was never ordered into full scale production, for reasons that included the unavailability of the preferred engine and competition from another tactical reconnaissance aircraft, the Focke-Wulf Fw 189. Design and development In 1937, the German Air Ministry – the Reichsluftfahrtministerium (RLM) – issued a specification for a single-engine reconnaissance aircraft with optimal visual characteristics. The preferred contractors were Arado with their Arado Ar 198, but the prototype proved unsuccessful. . The eventual winner was the Focke-Wulf Fw 189 Uhu, as much as its twin-boom design did not match the requirement of a single engined aircraft. Blohm & Voss (Hamburger Flugzeugbau) although not invited to participate, pursued as their private venture something far more radical. The proposal of chief designer Dr. Richard Vogt was the unique asymmetric BV 141. Design The perspex-glazed crew gondola on the starboard side strongly resembled that found on the Fw 189, and housed the pilot, observer and rear gunner, while the fuselage on the port side led smoothly from the BMW 132N. The first prototypes used 1,000 PS (986 hp, 736 kW) Bramo 323 radial engine. radial engine to a tail unit. At first glance, the placement of weight would have induced tendency to roll, but the weight was evenly supported by lift from the wings. In terms of thrust vs drag asymmetry, the countering of induced yaw was a more complicated matter. At low airspeed, it was calculated to be mostly alleviated because of a phenomenon known as P-factor, while at normal airspeed it proved to be easily controlled with trimming. The tailplane was symmetrical at first, but in the 141B it became asymmetrical – starboard tailplane virtually removed – to improve the rear gunner's field of view and fire. Operational history Three prototypes and an evaluation batch of five BV 141As were produced, backed personally by Ernst Udet, but the RLM decided on 4 April 1940 that they were underpowered, although it was also noted they otherwise exceeded the requirements. By the time a batch of 12 BV 141Bs were built with the more powerful BMW 801 engines, they were too late to make an impression, as RLM already decided to put the Fw 189 into production. Indeed, an urgent need for BMW 801 engines for use in the Fw 190 fighter aircraft reduced the chance of the BV 141B being produced in quantity. Vogt came up with several other asymmetric designs, including the piston-jet P.194.01, but none of those were actually built. Several wrecked BV 141s were found by advancing Allied forces. One was captured by British forces and sent to England for examination. No examples survive today. Variants Contrary to much that has been written, says V13 was the last one actually built, but notes the discovered aircraft "mysteriously" marked "(G)K+GH". all 20 BV 141Bs ordered were produced and delivered. The complete record of BV 141 production, either a German civil registration or pre-military, four letter Stammkennzeichen radio code:Files of the Hamburger-Werke. Prototypes ;Ha 141-0 :D-ORJE; original designation of the first aircraft completed with the stepped cockpit nacelle. Became the BV 141 V2. ;BV 141 V1 :WNr 141-00-0171; D-OTTO then BL+AU, damaged ;BV 141 V2 :WNr 141-00-0172; D-ORJE then PC+BA; chronologically, the first one built and the only one known under old "Ha" designation as "Ha 141" ;BV 141 V3 :WNr 141-00-0359; D-OLGA then BL+AA Pre-series BV 141 A-0 ;BV 141 A-01 :(V4); WNr 01010360; D-OLLE; damaged ;BV 141 A-02 :(V5); WNr 01010361; BL+AB ;BV 141 A-03 :(V6); WNr 01010362; BL+AC ;BV 141 A-04 :(V7); WNr 01010363; BL+AD ;BV 141 A-05 :(V8); WNr 01010364; BL+AE Pre-series BV 141 B-0 The first to have BMW 801 engine. About 2 m longer and 2 m wider than A-05. ;BV 141 B-01 :(V9); WNr 0210001; NC+QZ; first flown 9 January 1941, had severe structural problem ;BV 141 B-02 :(V10); WNr 0210002; NC+RA; first flown 1 June 1941 ;BV 141 B-03 :(V11); WNr 0210003; NC+RB ;BV 141 B-04 :(V12); WNr 0210004; NC+RC ;BV 141 B-05 :(V13); WNr 0210005; NC+RD ;BV 141 B-06 :(V14); WNr 0210006; NC+RE ;BV 141 B-07 :(V15); WNr 0210007; NC+RF ;BV 141 B-08 :(V16); WNr 0210008; NC+RG ;BV 141 B-09 :(V17); WNr 0210009; NC+RH ;BV 141 B-10 :(V18); WNr 0210010; NC+RI Series BV 141 B-1 ;BV 141 B-1 :WNr 0210011; GK+GA ;BV 141 B-1 :WNr 0210012; GK+GB ;BV 141 B-1 :WNr 0210013; GK+GC ;BV 141 B-1 :WNr 0210014; GK+GD ;BV 141 B-1 :WNr 0210015; GK+GE ;BV 141 B-1 :WNr 0210016; GK+GF ;BV 141 B-1 :WNr 0210017; GK+GG ;BV 141 B-1 :WNr 0210018; GK+GH ;BV 141 B-1 :WNr 0210019; GL+AG; rebuilt D-OTTOKambeck, Lars. Jet & Prop Magazine. ;BV 141 B-1 :WNr 0210020; GL+AH; rebuilt D-OLLE Specifications (BV 141 A-04 V7) |prime units?=met |crew=3 |length m=12.15 |span m=15.45 |height m=4.1 |wing area sqm=42.85 |empty weight kg=3,167 |gross weight kg=3,900 |eng1 number=1 |eng1 name=BMW 132N |eng1 type=9-cyl. air-cooled radial piston engine |eng1 kw=636 |eng1 note=at sea level at |prop blade number=3 |prop name=variable pitch |max speed kmh=340 |max speed note=at sea level; at |cruise speed kmh=310 |cruise speed note=at sea level; at |range km=1,140 |range note= maximum |ceiling m=9,000 |wing loading kg/m2=60.2 |power/mass=0.448 kW/kg (0.274 hp/lb) |guns= 2 × fixed forward firing MG 17 machine guns and 2 × rear-mounted flexible 7.92 mm MG 15 machine guns |bombs=4 × SC50 bombs on under-wing racks }} Specifications (BV 141 B-02 V10) |prime units?=met |crew=3 |length m=13.95 |span m=17.45 |height m=3.6 |wing area sqm=52.9 |empty weight kg=4,700 |gross weight kg=5,700 |gross weight note= * Max take-off weight: |eng1 number=1 |eng1 name=BMW 801A |eng1 type=14-cyl. air-cooled radial piston engine |eng1 kw=1,147 |eng1 note=for take-off at sea level |max speed kmh=368 |max speed note=at sea level; at |range km=1,900 |range note= maximum |ceiling m=10,000 |wing loading kg/m2=107.75 |power/mass=0.204 kW/kg (0.124 hp/lb) }} See also *Focke-Wulf Fw 189 *List of military aircraft of Germany References Notes Citations Bibliography * Green, William. Warplanes of the Third Reich (4th impression ed.). London: Macdonald and Jane's, 1979, pp. 81–86. ISBN 0-356-02382-6. * Green, William. Aircraft of the Third Reich (1st ed.). London: Aerospace, 2010, pp. 136–144. ISBN 978-1-900732-06-2. * Rys, Marek. "Blohm und Voss BV 141". Nowa Technika Wojskowa (New Military Technology) (in Polish) (Warsaw: Magnum-X), November 2004, pp. 55–64. ISSN 1230-1655. * Smith, J. Richard and Anthony Kay. German Aircraft of the Second World War. London: Putnam & Co, 1978, Third impression, pp. 66–71. ISBN 0-370-00024-2. * Taylor, Michael. The World's Strangest Aircraft. London: Grange, 1999. ISBN 1-85627-869-7. * Wood, Anthony and Bill Gunston. Hitler's Luftwaffe: A Pictorial History and Technical Encyclopedia of Hitler's Air Power in World War II. London: Salamander, 1977, p. 135. ISBN 0-86101-005-1. External links * Blohm & Voss BV 141, VR Curassow. Category:Single-engined tractor aircraft Category:1930s German military reconnaissance aircraft Category:Asymmetrical aircraft BV 141